My car is reving on its own just before i come too a stop say under 15 mph and during this i hardly have and throttle input id say like 20% even if i mash it toobthe floor ot just wont rev. The idle ramps up too 1200. Any ideas?

I think that happened to me once on the way to work. Coming to a stop light, slowing down, I put the car in neutral. Then with foot off the clutch and on the brake, the revs went up to maybe 1200 -1500. Only happened the one time but it was kinda strange.